1. Field of the Invention
The present invention relates to a pedestrian detection apparatus for recognizing a pedestrian from an input image picked up by an image pick-up device based on a pattern matching between the input image and an entire profile (or a whole body/part) model images.
2. Description of the Related Art
In a known technique of recognizing a pedestrian on a street, a whole or part of a body of the pedestrian is recognized on the basis of a pattern matching between an image picked up by a camera and model images.
When the whole body of the pedestrian is recognized on the basis of the pattern matching using the model images, a stable recognition accuracy can be obtained. In this method, however, many model images corresponding to motions of the pedestrian are required, and thus an operation processing is complicated and a high-capacity memory must be provided.
On the other hand, in a method of recognizing the pedestrian by using the model image for a part of the body, the recognition accuracy is decreased disadvantageously.
In order to overcome these problems, Japanese Unexamined Patent Application Publication No. 2002-24986 discloses a technique of recognizing the pedestrian based on images of the right and left sides of an object which have been picked up by using visible cameras placed on the right and left. In this known art, the pedestrian is recognized on the basis of a parallax of the right and left cameras, and thus no model image is required.
In the technique disclosed in the above-mentioned patent document, images of an area ahead of a vehicle are picked up by using visible cameras. However, when there is no light source for illuminating the pedestrian, e.g., during the night, an image of sufficient quality can hardly be obtained by the visible camera. On the other hand, a stereo camera has a more complicated entire system compared to a monocular camera and the product cost increases disadvantageously.
As disclosed in Japanese Unexamined Patent Application Publication No. 10-105891, by scanning the area ahead of the vehicle by using a radar sensor, the area can be recognized day and night. However, the circumstances ahead of the vehicle during the night and the state of recognition of the circumstances cannot be visually presented to a driver.